Posthole digger



Dec. 28 1926.

L. E. GlBSON POSTHOLE BIGGER Filed April 5, 192 .4 sheets-sheet 1 /NVEA/TOR i Dec. 28 19.26.`

l... E. GIBSON l PosTHoLE DIGGR Filed April 5. 1926' 4 Sheets-Sheet .2

l NVENTOR A Tra/NE y Dec. 2s 192e.

L, E. GIBSON POSTHOLE DIGGER 4 Sheets-Sheet :5

Filed April 5. 1926 Dec. 28 1926.

l.. E. GIBSON POSTHOLE DIGGER Filed April 5, 192.6 4 sheets-sheet. 4

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A TTORNE y l??atentedA Een. 28, 1926.,

UNllfl STATES LEO E. GIBSON, F BETE/01T, MCI-IfG-AN.

PQSTHOLE BIGGER.

Application filed April 5, 1926. Serial No. 99,706.

This invention relates to an earth boring machine, and has for itsobject an improved organization of parts by means of which post holesand the like may be easily and neatly bored in the ground at anyselected location with a minimum handling of earth, and in consequenceleaving the ground surroundin' the hole when bored in its original firmane tightly packed condition, as con tiasted with the relative loosenessof the earth in case a larger hole is excavated, as by hand, with asubsequent attempt to manually repack the earth about-the hole withsui'iicient firmness to hold it without resort to lateral guy wires.

ln the drawings:

Figure 1 is a side elevational view of my improved construction.

Figure Q is a front or end view.

Figure 3 is a plan View.

l" ure a is a horizontal partly sectional taken along the line 4--4 ofFigure y1, .nd looking in the direction of the arrows 'here shown.

Figure 5 is a `partly sectional vertical elevation of the details of theauger-actuating and brushwrotating portions ofV the mechanism.

' While any suitable or convenient type of chassis frame or engine maybe employed in connection with the structural ideas herein disclosed,with modifications obvious to any one skilled in the art-it will be seenthat i have illustrated my preferred construction in connection with thenow well-known tractor and `a` suitable frame, whose parts are arrangedin such a manner that all can be controlled and operated from a pointwithin reach of the drivers seat, thus making my device especiallyiafone man plant instead of requiring a crew of two or three, as in someof the prior devices with which am familiar. Certain of theseconstructions as well embody principles of const-ruction which are notonly initially expensive, but which l have found ,in practiceare likelyto become clogged as the loosened earth is removed, and which ifespecially heavy downward `gressurepupon the boring blad/eis requiredptofollow up the cutting movement thereof, involve more or less jamming andbinding of the operative parts. l

Toavoid these difficulties, my device is made to embody with the tractorunit and its frame an over-engaging or overreaching boom structure, fromwhose free end the boring element is suspended for free rot-ation, andwhich by properly timed actuation of certain of the controls can be madeto function efficiently both as a downwardly weighing element to assistthe cutting movement of the auger blades, and as a medium forintermittently lifting the entire boring member, with what earth it hasmeantime loosened resting upon its blades, free and clear of the holethat has been cut in the ground,vfor removal of the loose earththerefrom in any desired manner, as for example, by means of the brushor sweep member, which i will hereinafter describe more fully.

In this construction 12 represents the chassis or tractor frame, 13 thetraction wheels an-d 14 the tractor plant, whose severalpower-delivering mechanisms may all be controlled by levers positionedconveniently adjacent the drivers seat 15. Positioned generallylengthwise over the tractor frame, and pivoted to either side throughits lower ends, is a boom or frame piece 16, from the free swinging orouter end of which the boring shaft 36 is suspended in position of freerotation by means of the swivel Each of the side pieces of the frame 16has pivot-ally connected with it, toward its opposite end from which theboring shaft is suspended, the top ends of a pair of links 1T and 18.The lowerends of the links 17' .are journaled on the shaft 19, whereasthe lower ends of the links 18 are pivotally connected to the upper edgeof the Quadrant 20, which is also carried on the shaft 19 in positionfor a limited up and down movement by the operation of actuating meanswhich will be later described. llt will thus be obvious from aninspection of the full line and dotted line positions of the boom 16 andthe links 17 and 18 shownin Figure 1, that, as the quadrant is moved upand down, the boom will be swung accordingly, due to thefact that in itsintermediate portion each side of the boom frame carries a `roller 22,which engages in a curved channel ,guide 23, which rises on each side ofthe vehicle frame, thus constituting a moving or slidable pivot pointcooperating withthe action ofthe links 17 and 18 to throw the boom toanyintermediate positions ybetween the full line position and the dotted4line position shown; the curvature of the Guides 23 and the relativelength and positioning i ofthe links 17 y. and 18 is such that therpointof suspension of the boring shaft moves in and by means of wnich one orthe other of the idler pinions 25 and 26 may be thrown Vinto or out ofengagement witn the idler wheel 2T, whose teeth are uniformly in meshwith those of the larger gear wheel Q8 mounted on the shaft 29. Thislatter carries, so as to rotate with it the reducing sprocket wheel 30.over which passes the endless chain 31. Ahis latter in turn passes aboutthe sprocket wheel 32 which is mounted upon the shaft 83, which latteralso carries the smaller reducing gear 34, which lies in a planecoincident'with thatI of the quadrant 20, and in such position withrespect thereto that its' teeth mesh with teeth i in the peripherythereof. The boom and its supported boring shaft may thus be raised orlowered under manual control as regards their speed and degree ofmovement, in unison with the boring action, and according to the speedwith which the boring blades make their way down into the ground.

For the transmission of power to the boring blade, l make use of a.series of gear member.: and endless chain elements, which directlyv orindirectly derive their actuation from the gear wheel 42, which iscarried on the end of the shaft 41, which, as regards the boringjoperations, may be regarded as thev main shaft. rlho main shaft of theen- Vgine itself is, however, shown at 46; on it is carried the sprocketwheel 45, which cooperate with the sprocket wheel on the shaft 41 incafryiirgT the endless chain 44, and thus operatively conmctir'o` boththe boring and the lifting` mechanism with the engine. The teeth of the.rear wheel 42 (ou the shaft 41) are always in mesh with those of thepinion 47. which carried on the stud or cross shaft 48. rlhe rotation ofthe pinion 4T in the direction shown by the small arrow in Figure 1imparts rotative movement to the idler pinion 9.5 in ca the latter isthrown into mesh therewith by suitablepull upon the hand lever 24; theteeth of this pinion 47, being in mesh with those of the pinion 42, therotative movement thus communicated to it is in turn passed on to theidler pinion 49, whose'meshingg or otherwise with the pinion 4T isVregniatable by means of the shifting collar 50 and its hand lever 51,to move the pinion 49 into and out of the plane of the pinion 47 Theidler pinion 4,9` is preferably. mounted upoiithe stud longitudinel'zeywa'y 66, which estenos carried in the chassis frame. The teeth ofrhe idler pinion 49 mesh with those of the pinion 53, carried on theshaft 54, on which is also mounted the sprocket wheel 55, over whichpasses the endless sprocket chain 56, for the communication of rotativemovement to the sprocket wheel 57, which is rotatably supported on theshaft 58 which passes through bearings 59 in the boi; or shell 60,whence its rotative movement is communicated to the shaft of the augeror boringl member 86 by the bevel gears 61 and G2.

This box or shell GO is carried on one end of the t actor frame 12, andbeing adequately noused in as regards the possible :iccess of looseearth to its contained part-s, the possibility of clogging from thissource is reduced to a minimum. The auger shaft 3,6, however, extendsmovably therethrough, being,r operatively connected with the 'sl G4,which moves with the bevel ge r by means of the' key 65 operatingl Jnenough up toward the swivel-supporter upper end to permit of the shaftreceiri rotative actuation from the bof; p at any point along alongitudinal dis A, equal to the exiected depth of the bore it isdesired to cut in the arth. il"

i referably, though not necessarily, the box GO connected with the frame12 pivotallv by mean of the transversely extending s 67, so that forconvenience and avoidance of injury to the boring blade while theapparatus is being moved from one location to another the box and augermay be tilted at an angle, thus adequately raising the top ot the bladeabove the surface of the ground,

Wlhen the operator.l by pull upon the lever startin-gthe cooperativeaction of rants 20 and the links 17 and 18, in a way to cause downwardor weighino pressure by the boom upon the shaft of the auejer 36coaXially thereof, thus aiding` the downward cutting action of theblades into the earth. Vhen the hole has been bored to the desireddepth, or to such portion thereof as has resulted in the accumulationabout the boring blade of a considerable quantity of loose earth, thefurther rotative movement of the boring shaft temporarily halted bysuitable actuation of the hand lever 5l, and at the Sametime thedownwardly weighing` prcssure of the boom 16 is terminated by a pullupon the lever 24.y causing),` the mechanism already described toswingthe boom upwardly, but thanks to the cooperation of the links 17and 18 and the curved channel guides 23, in such a wav as not to disturbthe axial position of the shaft of the auger v36 with respect yto thegear box 60, thus leavboom member relatively to` the work in progress.

5. In an earth-boring machine, the com bination of a supporting chassis,a link-supported boom positioned thereover, laterally positioned guidemembers with which said boom has a slidable engagement, adapted tocooperate with the link members in guiding the swing of the boom in avert-ical plane, a boring member rotatably supported from the free endof said boom, a powei` plant carried by said chassis, and selectivepower-transmitting means whereby the actuative power of the engine maybe distributcd to the traction elements of the vehicle, to the boom,'orte the. boring member.

G. .In an earth-boring mechanism, the combination, with a tractor frame,of an engine carried thereby, a plurality of link members supported bysaid frame in position of potential swing in a vertical plane, a boommember supportedV by said link members, stationary guide members withwhich said boom member is slidably connected and whereby, in cooperation'with said link members, the possible movement of said boom member isregulated, a rotatable boring member suspended from said boom inuniformly vertical position, a normally inactive brush member adapted torotatively engage the upraised blade of the boring member toctlect theclearance therefrom of the earth loosened by its boring action, and aplurality ot selectively actuable operative connections between saidengine and the several movable elements whereby its actuative movementmay be transmited to them when and to the degree required.

7. In an earth-boring mechanism in combination with a power plant andtractor frame carrying the same, a boom member adjustably positionedsuperiorly of said frame, a boring member rotatably supported from saidboom member adjacent one end of the frame, normally inactive meanswhereby the power plant may be operatively connected with said boringmember, and means tixedly supported on either side of said boom memberand with which said boom member is slidably connected for regulatablyvarying the position of said boom member relatively to the frame as theaction of the boring member progresses, without impairment of the axialposition of the latter relatively to the frame and to the earth locationbeing worked upon.

8. In an earth boring mechanism, the combination, with a tractor frameand a power plant carried thereby, of a boom member positionedthereabove, means connectible with the power plant for varying theangular position of the boom member, avboring member rotatably supportedfrom the free end of said boom member in axially vertical positionadjacent an end of the vehicle chassis, means supported by said tractorframe and with respect to which said boom member is operativelyconnected whereby its actuated angular swing effects no variation in theaxial position of the boring member, means connectible at will with thepower plant for effecting the rotative actuation of said boring memberat any point in its path of vertical travel, and normally inactive meanspositioned at one side of the axial location of the boring memberwhereby the blades of the latter may be cleared of loose earth when thesame is raised to the upper portion of its axial path of travel.

In testimony whereof, I sign this specifcation.

LEO E. GIBSON.

